How can char cloth tinder be made from fabric?

The best tinder of all is made from linen or cotton. The thicker the fabric chosen, the better; you could use an old pair of jeans. The fabric should be cut into rectangles of equal size, stacked in a pile and wrapped in aluminum foil. The resultant briquette should be placed in a tinderbox made of tin, such as those which come with each of our kits. Then you should place the tinderbox over the flame of a gas burner. All of this should preferably be done out in the street. The gas burner's flame should be set to a minimum. After a short period of time, a charcoal gas will start to be released from the tinderbox and will burn when in contact with the burner's flame. It will appear as if the flames are coming from the tinderbox itself. You should wait until the smoke or flames coming from the tinderbox have stopped before you turn off the burner. The tinderbox should be left for a minimum of 30 minutes to cool down. Even if it quickly becomes cool to the touch, you should still wait out this time. Afterwards you'll get your tinder. If everything has been done right, you'll have gotten an excellent piece of char cloth tinder from your fabric.